The invention relates to safety devices, primarily fasteners such as, for example, screws, bolts, pins, rivets. The invention has particular use with equipment or installations where personal safety is at issue such as, for example, in agricultural equipment, industrial machines and recreational installations.
In one example, persons with long hair swimming by drains in swimming pools, spas and hot tubs may have their hair pulled into the drain grates. When a vortex exists in the drain sometimes the hair is twisted, causing the hair to become entangled in the drain grate. When substantial hair is so entangled, removal becomes difficult and a hair entrapment on the drain grate becomes a possibility. Serious injury or drowning may result.
Anti-vortex fittings have been installed in drains to prevent twisting of hair, but the anti-vortex fittings may not always be successful in preventing the formation of a vortex or currents which tend to twist the hair and entrap the hair on the drain.
Proposals have been made that swimming pool attendants be equipped with shears to cut hair in case of entanglements, but those proposals are not realistic in view of the difficulty of dealing with a struggling person whose hair is entrapped while being held underwater.
A need exists for a safety device which will reduce drowning from accidental hair entrapments in drains.
Other examples may be in agricultural harvesters or industrial machinery in which clothing or limbs may become engaged or any blockage may become lodged, with attendant dangers to the persons or machinery.
In one example, the invention provides a new drain fastener which is torsionally strong and axially weak so that a drain grate may be fastened in place with the fastener, and the drain grate is quickly removed with minimal axial force on the fasteners.
A safety device is designed to prevent entrapments and entanglements in swimming pool, spa and hot tub drain grates. The safety product is a screw strong in torque but weak in axial tension. The screws are retrofittable on all existing drains, as well as available to be incorporated into all new drains. The screw may be made of any suitable material such as plastic or corrosion-resistant metal.
The screw assembly has a connector with a blade in a socket, polygonal projections and sockets, or a multiple pin system that would allow for strong torque for installing and removing. A weaker axial separation strength, in ft. lbs, would be determined by testing to see how much force is needed for a small child or elderly person to shear the bond between parts of screws. An extraction wrench is available to extract studs if a tensional shear release ever happens.
Various size pins are provided through the two-part screw to vary tensional shear strength.
A preferred pool, spa and hot tub drain grate safety apparatus for preventing injury due to entrapments and entanglements in drain gratings has a drain grate and fasteners for connecting the drain grate to a drain on a pool base. Preferably, each fastener has first and second sections, the first and second sections being releasably connected for quick release of the sections and of the drain grate from the pool base on applying a pressure on the fasteners.
Preferably, extensions are provided on the drain grate, and openings in the extensions complementary to openings along the drain in the pool base for receiving and holding the fasteners and fastening the drain grate on the drain.
In preferred embodiments of screws, bolts, pins and other fasteners used in large machinery or installations, first and second sections of the fasteners have torque transmitting connections between the sections for withstanding strong torque between the sections during installation or removal and for separating axially upon applying a force to release the guards or parts from the main machinery or installation.
Preferably, the fasteners have at least two portions. The first portions are preferably formed for sliding through an opening and may have heads or end connectors such as nuts or cotter pins to prevent further sliding. Recesses or shapes are provided on the heads for receiving connectors or driving devices.
The portions on the second section may be formed as threaded portions for engaging complementary threaded openings along a base or for engaging threaded nuts for holding parts or assemblies of the machines or installations together. Connectors include projections and complementary receivers in the first and second sections for releasably engaging the first and second sections upon excess axial force.
Preferably, the connectors are axial projections and the receivers are complementary recesses for holding first and second sections together and permitting transmission of torque between the sections without allowing the sections to separate.
In preferred embodiments, the connectors are projections and the receivers are complementary sockets for holding the first and second sections together by a friction fit.
A tool is preferably provided for engaging a recess or projection on the second section and for removing the second section from its installation position after separation from the first section. The tool may be any tool such as an extraction wrench.
The fasteners are made of any suitable material such as plastic, corrosion-resistant metal, or the like. The fasteners may have a corrosion-resistant coating.
In an example of a preferred method for easily removing a drain grate from a pool, spa or hot-tub base fasteners are provided with releasable first and second sections for connecting the drain grate to the base. When an axial force is exerted on the drain grate, it causes separation of the first and second sections of the safety release screws in response to the axial force, and releases the drain grate from the base in response to the separation of the fasteners.
In a preferred embodiment, safety fasteners comprise upper and lower sections and an axially releasable, torque transmitting connection between the upper and lower sections for withstanding a strong torque between the sections during installation in pool, spa, or hot-tub bases and for easy separation of the sections upon applying a force.
Preferably, lower sections have threads for engaging complementary threads in openings in the pool base. The upper sections preferably have radially extending heads for preventing passage of the heads through openings in drain grates. The drain grates have grate openings and the heads have shapes for receiving driving devices. Cylindrical recesses are provided in the upper sections and axial pins in the lower sections for engaging the recesses and for holding the first and second sections together permitting transmission of torque between the sections without allowing the sections to separate.
In an example of a preferred pool, spa and hot tub drain grate safety apparatus for preventing injury due to entrapments and entanglements in drain gratings has a drain grate, a frame on the drain grate, screw openings in the frame for aligning with threaded screw receiving holes in a pool base, safety release screws in the screw openings, safety release screws having upper and lower sections, the lower sections having threads for engaging with the threaded screw receiving holes in the pool base, the upper sections having radially extended heads for preventing passage of the heads through the screw openings in the grate frame, the heads having recesses for receiving an appropriate screw driver, and axially releasable, torque transmitting connections between the upper and lower sections for withstanding strong torque between the sections required for installing the screws in the threaded screw receiving holes in the pool base and for separating upon axial force and thereby releasing the upper sections from the lower sections and the grate from the pool base.
A preferred method of removing fasteners includes providing releasable upper and lower sections on fasteners, exerting an axial force on the fastener for quickly releasing the upper and lower sections and disengaging the fastener.
Preferably, the torque transmitting connections of the safety release screws include aligned axially offset recesses in the upper and lower sections and axial pins inserted in the recesses for holding the sections together permitting transmission of torque between the sections and allowing the sections to separate axially.
The torque transmitting connections of the safety release screws further comprise projections on tops of the lower sections and sockets in the bottoms of the upper sections. Alternately the projections may be provided on the upper sections and the sockets in the lower sections.
Preferably, an extraction wrench has a complementary projection for inserting in the sockets and twisting of the lower sections for removal of the separated lower sections of the screw from the screw holes in the pool base.
A preferred method for removing a part of assembly from a machine base includes pulling on the part or assembly, causing an axial force on safety release fasteners holding the part or assembly on the machine base, separating upper and lower sections of the safety release fasteners with the axial force, and releasing the part or assembly from the machine base in response to the separating of the safety release fasteners.
Preferred safety release fasteners include upper and lower sections. The lower sections have threads for engaging with the threaded screw receiving holes or nuts in the machine base. The upper sections have heads with radially extended engagements for preventing passage of the heads through the screw openings in parts or assemblies and the heads having shapes for receiving a driver. Axially releasable, torque transmitting connections between the upper and lower sections withstand strong torque between the sections required for installing the fasteners in the threaded screw receiving holes or nuts in the machine or installation base and separate upon excess axial force. Frictional surfaces in the torque transmitting sections hold the fasteners together during installation and release the sections upon excess axial force.
These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the claims and the drawings.